Trigger Programs?

[peteh@xxxxxxxxxxxxxxxx (Pete Hall)]

>> Does anyone have good examples (source code) of trigger programs? <<

David,

Here's the shell program that I use. In actual practice it seems that
the update procedure usually does some stuff and then executes doDelete
followed by doInsert. PFile is the file that the trigger is attached to.
AFile is another file that the trigger updates. Fields in both the
before and the after images can be compared directly by comparing
OR_field with NW_field. The program will not handle commitment control
being started or ended while it is running. It should execute in the
same activation group as the calling process - ACTGRP(*CALLER),
particularly if commitment control is used. However, if it uses bound
calls, particularly to a service program, and is executed from an OPM
job, it must run in its own (OLE) activation group. In this case,
commitment control cannot be used.

hth
Pete


      /TITLE TRIGGER ** Trigger program shell **

      * Replace <PFile> with physical file name
      * Replace <AFile> with ancillary file name

      * ---------------------------------------------
      * Ancillary files
      * ---------------------------------------------
     F<AFile>   UF A E           K DISK    Commit(RunCommit) UsrOpn

      * ---------------------------------------------
      * Entry Parameters
      * ---------------------------------------------
     DBuffer           DS         32767
     D PFName                        10
     D PFLibrary                     10
     D PFMember                      10
     D TrgEvent                       1
     D TrgTime                        1
     D TrgCmtLvl                      1
     D                                3
     D TrgCCSID                       7B 0
     D                                8
     D OrOffset                       7B 0
     D OrRcdLen                       7B 0
     D OrNBMapOfs                     7B 0
     D OrNBMapLen                     7B 0
     D NwOffset                       7B 0
     D NwRcdLen                       7B 0
     D NwNBMapOfs                     7B 0
     D NwNBMapLen                     7B 0
     D DataSpace               1  32767
     D Bytes                          1    Overlay(DataSpace) Dim(32767)

     DBufferLen        S              7B 0

      * ---------------------------------------------
      * Original Record
      * ---------------------------------------------
     D@OrRecord        S               *   Inz(*Null)

     DOrRecord       E DS                  ExtName(<PFile>) Prefix(OR_)
     D                                     Based(@OrRecord)

      * ---------------------------------------------
      * New Record
      * ---------------------------------------------
     D@NwRecord        S               *   Inz(*Null)

     DNwRecord       E DS                  ExtName(<PFile>) Prefix(NW_)
     D                                     Based(@NwRecord)

      * ---------------------------------------------
      * Constant Definitions
      * ---------------------------------------------
      * Commit Levels
     DCL_NONE          C                   '0'
     DCL_CHG           C                   '1'
     DCL_CS            C                   '2'
     DCL_ALL           C                   '3'

      * Null byte status
     DNB_NOTNULL       C                   '0'
     DNB_NULL          C                   '1'

      * Trigger events
     DTE_INSERT        C                   '1'
     DTE_DELETE        C                   '2'
     DTE_UPDATE        C                   '3'

      * Trigger times
     DTT_AFTER         C                   '1'
     DTT_BEFORE        C                   '2'


     C     *ENTRY        plist
     C                   parm                    Buffer
     C                   parm                    BufferLen


      * ---------------------------------------------
      * Main-line Procedure
      * ---------------------------------------------

      * Assign the record templates to their data space
     C                   eval      @OrRecord = %Addr(Bytes(OrOffset+1))
     C                   eval      @NwRecord = %Addr(Bytes(NwOffset+1))

      * Execute the correct procedure based on trigger event
     C     TrgEvent      caseq     TE_INSERT     DoInsert
     C     TrgEvent      caseq     TE_DELETE     DoDelete
     C     TrgEvent      caseq     TE_UPDATE     DoUpdate
     C                   endcs

     C                   return

      * ---------------------------------------------
      * Process a delete event
      * ---------------------------------------------
     CSR   DoDelete      BEGSR


     CSR                 ENDSR

      * ---------------------------------------------
      * Process an insert event
      * ---------------------------------------------
     CSR   DoInsert      BEGSR


     CSR                 ENDSR

      * ---------------------------------------------
      * Process an update event
      * ---------------------------------------------
     CSR   DoUpdate      BEGSR


     CSR                 ENDSR

      * ---------------------------------------------
      * Program Initialization
      * ---------------------------------------------
     CSR   *INZSR        BEGSR

     C                   if        TrgCmtLvl > CL_NONE
     C                   move      *ON           RunCommit
     C                   endif
      *                                          > if TrgCmtLvl >
CL_NONE      C                   open      <AFile>

     CSR                 ENDSR
 


--
 - Pete Hall peteh@earth.inwave.com
http://www.inwave.com/~peteh/

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